Ballcentric Plug Valve

Transcription

1 Ballcentric Plug Engineering Creative Solutions for Fluid Systems Since 1901

2 A Tradition of Excellence With the development of the first rubber seated butterfly valve more than 70 years ago, the Henry Pratt Company became a trusted name in the flow control industry, setting the standard for product quality and customer service. Today Pratt provides the following range of superior products to the water, wastewater and power generation industries. Butterfly s: from 3" to 162" Rectangular s: 1' x 1' to 14' x 16' Ball s Rubber Seated: from 4" to 60" Metal Seated: from 6" to 48" Plug s: from 1/2" to 36", 3 ways Hydraulic Control Systems Controls Energy Dissipating s and Fixed Energy Dissipaters Cone s Check s A Commitment to Meeting The Customers Needs Henry Pratt valves represent a long-term commitment to both the customer and to a tradition of product excellence. This commitment is evident in the number of innovations we have brought to the industries we serve. In fact, the Henry Pratt Company was the first to introduce many of the flow control products in use today, including the first rubber seated butterfly valve, one of the first nuclear N-Stamp valves, and the bonded seat butterfly valve. Innovative Products For Unique Applications Though many of the standard valves we produce are used in water filtration and distribution applica tions, Pratt has built a reputation on the ability to develop specialized products that help customers to meet their individual operational challenges. Creative Engineering for Fluid Systems Pratt s ability to provide practical solutions to complex issues is demonstrated by the following case histories. Earthquake Proof s Pratt designed and manufactured hydraulically actuated valves for a water storage application so that the valves would automatically operate in the event of earthquakes. This lead to the development of a valve that will withstand acceleration forces of up to 6g s. Custom Actuation/Isolation s Pratt designed and manufactured valves that would isolate a working chamber in the event of a nuclear emergency during the decommissioning of armed nuclear warheads. The valves were able to close in a millisecond using specially designed Pratt electropneumatic actuators. s Designed for Harsh Environments Pratt designed and manufactured a 144" diameter butterfly valve for the emergency cooling system at a jet engine test facility. The valve was designed to supply water to help dissipate the tremen dous heat generated by the engines during testing. Through experience, commitment and creative engineering, Pratt is uniquely suited to provide superior products for our customers special needs. For more information, contact our corporate headquarters in Aurora, Illinois.

3 Scope of Line: Pratt Ballcentric Plug Sizes: 1/2" through 72" Body Styles: End connections n Flanged (2-1/2" - 72") n Mechanical Joint (3" - 48") n Grooved (3" - 12") n Threaded (1/2" - 2") n Flanged 3-way (3" - 16") Pressure Class: n 175 psi, 12" and smaller n 150 psi, 14" and larger n Higher pressure on request Port Shape/Area: n 1/2" to 12" round n 14" - 36" rectangular n 100% port area available Actuation Options: n Direct nut n Chainwheel n Buried Service n Cylinder n Handwheel n Electric Motor Note: Manual actuators will be worm and gear type. Plug Elastomers: Linings: n Buna n Glass n Neoprene n Natural Rubber n EPDM n Neoprene n 2-Part Epoxy Design Details n n n n Welded Nickel Seat Elastomer Coated Plug Permanently Lubricated, Stainless Steel or Bronze Bearings Self Adjusting Stem Seal Henry Pratt Company 1

4 Advantages of Plug s Feature Benefit Efficient economical flow Better flow characteristics resulting in less pressure drop across the valve Port passes larger solids Port offers less resistance to slurry, sludge and fluid flow Large nominal port size Unobstructed, direct flow path Reduces plugging problems Less erosion, longer service life and reduced pumping costs Less resistance to flow resulting in reduced operating costs Plug is hidden from flow stream so no debris buildup on plug. Also allows for in-line pigging Discussion of Cv's The specification of valve port area has been bounced around with the notion that the larger the port area, the higher the flow rate, or in other words, the greater the Cv value in gallons per minute. This argument of flow has also pulled in the specific shape of the port. Whether its round or rectangle, the port area and associated shape of the port seems to be taking precedence in specifications without taking into consideration the actual Cv of the valve. Cv is defined as the amount of flow through a valve, in gallons per minute, with a 1 psi pressure drop across the valve. The greater the Cv the more efficient the valve will perform in terms of reduced headlosss or energy consumption. The shape of the port, whether round or rectangular, is important from an understanding of what shape is best to efficiently manufacture plug valves. The issue of effective seat design plays a huge role in determining the shape of the port. In smaller size valves - up to 12" - the most cost effective approach to produce plug valves is with round ports. As you get into larger sizes, the most cost effective approach to producing plug valves is with rectangular ports. However, this comes with a caveat. The more divergent from center the flow must take in a rectangular port, the greater the amount of head loss the valve generates. To measure or compare one valve manufacturer to another in terms of head loss, the plug manufacturer who has the larger port width, on the surface, will have less head loss than a manufacturer with a narrower port width. 2 Henry Pratt Company

5 Suggested Specification for Ballcentric Plug General Plug valves shall be of the non-lubricating, eccentric type and shall be designed for a working pressure of 175 psi for valves 12" and smaller, 150 psi for valves 14" and larger. s shall provide tight shut-off at rated pressure. s shall be manufactured by Henry Pratt. s 12" and smaller shall have round port design. 14" and larger valves shall have rectangular port design. Body The plug valve body shall be cast iron ASTM A126 Class B with welded-in overlay of 99% nickel alloy content on all surfaces contacting the face of the plug. Sprayed, plated, nickel welded rings or seats screwed into the body are not acceptable. Plug The valve plug shall be ductile iron ASTM A-536, Grade with Buna N resilient seating surface to mate with the body seat. Shaft Seals shaft seals shall be of the U cup type, in accordance with AWWA C517. Seals shall be self adjusting and repackable without removing the bonnet from the valve. Actuators 6" and smaller exposed valves shall be provided with wrench actuators. 8" and larger exposed valves shall be provided with worm gear type manual actuators. All buried valves shall be provided with worm and gear actuators suited for the intended service. actuators shall be fully grease packed and have stops in the open/ close position. The actuator shall have a mechanical stop which will withstand an input torque of 450 lbs. against the stop. The actuator shall be able to provide 1.25 times the required operating torque under full rated line pressure combined with a flow velocity of 8 feet per second. End flanges shall be in strict accordance with ANSI B16.1, Class 125. Bearings Plug valve shall be furnished with permanently lubricated sleeve type bearings conforming to AWWA C517. Bearings shall be of sintered, oil impregnated type 316 stainless steel ASTM A-743 Grade CF-8M or bronze ASTM B-127. Henry Pratt Company 3

6 Installation Options The type of materials carried in the pipeline and the location of the valve determine the correct installation orientation: Liquids without suspended solids may be installed with plug shaft vertical or horizontal. Downstream Upstream Seat Side Flow Flow Install valve with seat facing downsream of flow. 1. Before installation blow out pipeline to remove all foreign materials. 2. For vertical pipe installations install valve with seat facing downstream. Seat side designation identified on flange For vertical pipe installations install valve with seat facing downstream Seat Side Flow Upstream Pump Suspended solids and dirty gases Seat Side Seat Side Flow Flow Shut Open Install valve with plug facing upstream. Ensure plug rotates up to the fully open position thus preventing plug from sweeping through settled debris. Ensure plug rotates up to the fully open position thus preventing plug from sweeping through settled debris. Seat Side Install valve with seat facing downstream of flow. Flow For pump isolation service install the discharge valve with the seat downstream from the pump and with the plug rotating to the top of the pipeline in the open position. Pump 4 Henry Pratt Company

7 1/2" - 2" Plug Threaded Ends Size A C D E F H J 1/ / / / /2" - 8" Plug Flanged, Direct Nut Size A B C D E F G H J K L Henry Pratt Company 5

8 3" - 8" Mechanical Joint, Direct Nut Size A B C D E F G H L W " - 12" Mechanical Joint, Buried Service Actuator Size A B C D E F G H L M P T W Henry Pratt Company

9 2 1/2" - 12" Flanged End, Handwheel & Buried Service Actuator Size A B C D E F G H Size J K L M N P Q S T Henry Pratt Company 7

10 14" - 20" Flanged End, Gear, Handwheel Size A C D E F G H J K L M N " - 36" Flanged End, Handwheel Size A B C D E F G H L *Consult Henry Pratt for sizes 42" and above 8 Henry Pratt Company

11 14" - 20" Mechanical Joint with Buried Gear, 2" Nut Size A B C E F G H L " - 36" Mechanical Joint, Gear Size A B C E F G H L *Consult Henry Pratt for sizes 42" and above Henry Pratt Company 9

12 PRATT PRODUCT GUIDE Model 2FII Monoflange MKII Plug Triton XR70 Indicating Butterfly UL & FM approved Tilting Disc Check Triton XL N-Stamp Nuclear Butterfly Cone Rectangular PIVA Post Indicating Assembly UL & FM approved Sleeve Rubber Seated Ball Triton HP250 Check Groundhog Control Systems Compact Controllable Energy Dissipater Henry Pratt Company Metal Seated Ball 401 South Highland Avenue Aurora, Illinois United States Fax ISO 9001: 2000 Certified 2011 Henry Pratt Company Printed in the U.S.A. HPPLUG-0711